1. Field of the Invention
The present invention relates to a method of marking product information on the back side of devices constituting a wafer.
2. Description of the Related Art
A plurality of devices such as ICs and LSIs are formed on the front side of a wafer so as to be partitioned by a plurality of separation lines. The back side of the wafer is ground to obtain a predetermined thickness of the wafer. Whether or not each device is defective is tested by a prober, and as the test result each defective device is marked. Thereafter, dicing is performed by cutting the wafer along the separation lines to obtain the individual devices separated from each other. Further, product information such as function, product number, and lot number is marked on the back side of each nondefective device (see Japanese Patent Laid-open Nos. 5-121573 and 5-166949, for example). An assembly step subsequent to this marking step is managed according to the product information marked on each nondefective device. However, it is troublesome that the product information is marked on each of the individual devices after dicing the wafer, causing a reduction in productivity.